Teneligliptin Hydrobromide Hydrate 

C22H30N6OS, 2½ HBr, xH2O                                                     Mol. Wt.628.9

Teneligliptin Hydrobromide Hydrate is {(2S,4S)-4-[4-(3-Methyl-1-phenyl-1H-pyrazol-5-yl)piperazine-1-yl]pyrrolidine-2-yl} (1,3-thiazolidine-3-yl) methanone hemipentahydrobromide hydrate.

Teneligliptin Hydrobromide Hydrate contains not less than 98.0 per cent and not more than 102.0 per cent of C22H30N6OS, 2½ HBr, xH2O, calculated on the anhydrous basis.

Category. Antidiabetic.

Dose. 20 to 40 mg daily.   

Description. An off white to cream coloured powder.                                                                                                                       

Identification

2. Determine by infrared absorption spectrophotometry (2.4.6). Compare the spectrum with that obtained withteneligliptin hydrobromide hydrateRS or with the reference spectrum of teneligliptin hydrobromide hydrate.
3. In the Assay, the principal peak in the chromatogram obtained with the test solution corresponds to that in the chromatogram obtained with the reference solution.

Tests

Hydrobromic acid content. Not less than 28.0 per cent w/w and not more than 34.0 per cent w/w, calculated on the anhydrous basis, determine by liquid chromatography (2.4.14), as described under Assay with following modifications.

Reference solution. A 0.003 per cent w/v solution of hydrobromic acid RS in the solvent mixture.

Calculate the content of HBr.

Enantiomeric purity.  Not more than 0.5 per cent. Determine by liquid chromatography (2.4.14).

Test solution. Dissolve about 50 mg of the substance under examination in 25.0 ml of ethanol.

Reference solution (a). A 0.02 per cent w/v solution of R-isomer RS [{(2R,4R)-4-[4-(3-Methyl-1-phenyl-1H-pyrazol-5-yl)piperazine-1-yl]pyrrolidine-2-yl}(1,3-thiazolidine-3-yl)methanone hemipentahydrobromide hydrate RS]  in  ethanol.

Reference solution (b). Weigh about 100 mg of teneligliptin hydrobromide hydrate RS to a 50- ml volumetric flask, add 5.0 ml of reference solution (a), dissolve and dilute to volume with ethanol.

Chromatographic system

     –   a stainless steel column 25 cm ´ 4.6 mm packed with chiral Pak IC (5 µm),

     –   mobile phase: a 0.1 per cent w/v solution of diethylamine in ethanol.

     –   flow rate: 1 ml per minute,

     –   spectrophotometer set at 220 nm,

     –   injection volume: 10 µl.

The relative retention time of R- isomer peak is about 0.61 with respect to teneligliptin peak.

Inject reference solution (b). The test is not valid unless the resolution between the peaks due to R-isomer and teneligliptin is not less than 3.0.

Inject the test solution and measure the area of the R- isomer.

Calculate the content of the R- isomer by area normalization.

Related substances. Determine by liquid chromatography (2.4.14).

Solvent mixture. 80 volumes of water and 20 volumes of acetonitrile.

Test solution. Dissolve about 50 mg of substance under examination in 50.0 ml of the solvent mixture.

Reference solution (a). A 0.01 per cent w/v solution of each of impurity A RS, impurity B RS and impurity C RS in the solvent mixture.

Reference solution (b). Weigh and transfer about 50 mg of teneligliptin hydrobromide hydrate RS to a 50- ml volumetric flask, add 5.0 ml of reference solution (a), dissolve and dilute to volume with the solvent mixture.

Chromatographic system

     –   a stainless steel column 25 cm x 4.6 mm packed with phenyl group bonded to porous silica (5 µm) (Such as Inertsil Ph-3),

     –   mobile phase: A. a buffer solution prepared by dissolving 1.36 g of potassium dihydrogen phosphate and 1g of 1-octane sulphonic acid sodium salt in 1000 ml of water, adjusted to pH pH 2.7± 0.03 with dilute orthophosphoric acid,

1.        acetonitrile,

     –   a gradient programme using the conditions given below,

     –   flow rate: 1.5 ml per minute,

     –   spectrophotometer set at 215 nm,

     –   injection volume: 10 µl.

         Time      Mobile phase A      Mobile phase B         

      (in min.)     (per cent v/v)       (per cent v/v)             

            0                  75                           25                        

            7                  75                           25                        

           35                60                           40                        

           45                 50                           50                       

           50                 75                           25                       

           60                 75                           25 

Name                                                  Relative             Correction

                                                  retention time            factor

Hydrobromic acid                            0.09                        ---

Impurity A 1                                     0.46                       0.58

Impurity C 2                                     0.58                       1.70

Impurity B 3                                      1.96                             0.81         

                                                                                                                                                           

11-3-methyl-1-phenyl-5-pyrazolyl) piperazine,

2 tert-butyl(2S)-4-hydroxy-2-(thiazolidine-3-carbonyl) pyrrolidine-1-carboxylate,

3 tert-butyl(2S,4S)-4-(4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazine-1-yl)-2-(thiazolidine-3-carbonyl) pyrrolidine-1-carboxylate,

Inject reference solution (b).  The test is not valid unless the resolution between the peaks due to impurity C and teneligliptin is not less than 4.0.

Inject the test solution. In the chromatogram obtained with the test solution, the area of the peak due to impurity A, impurity B and impurity C is not more than 0.5 per cent. The area of any other secondary peak is not more than 0.3 per cent and the sum of the areas of all the secondary peaks is not more than 1.0 per cent, calculated by area normalisation.

Heavy metals (2.3.13). 1.0 g complies with the limit test for heavy metals, Method B (20 ppm).

Sulphated ash (2.3.18). Not more than 0.2 per cent, determined on 2 g.  

Water (2.3.43). Not less than 4.0 per cent and not more than 6.0 per cent, determined on 0.25 g.  

Assay. Determine by liquid chromatography (2.4.14). 

Solvent mixture. 60 volumes of water and 40 volumes of acetonitrile.

Test solution. Dissolve about 50 mg of substance under examination in 50.0 ml of the solvent mixture. Dilute 5.0 ml of this solution to 50.0 ml with the solvent mixture.

Reference solution. A 0.01 per cent w/v solution of teneligliptin hydrobromide hydrate RS in the solvent mixture.

Chromatographic system

     –   a stainless steel column 25 cm x 4.6 mm packed with phenyl group bonded to porous silica (5 µm) (such as Inertsil Ph-3),

     –   mobile phase: a mixture of  60 volumes of a buffer solution prepared by dissolving 1.36 g of potassium dihydrogen phosphate and 1g of 1-octane sulphonic acid sodium salt into 1000 ml of water, adjusted to pH pH 2.7± 0.03 with dilute orthophosphoric acid and 40 volumes of acetonitrile,

     –   flow rate: 1.5 ml per minute,

     –   spectrophotometer set at 215 nm,

     –   injection volume: 10 µl.                  

Inject the reference solution. The test is not valid unless the tailing factor is not more than 2.0, the column efficiency is not less than 2500 theoretical plates and the relative standard deviation for replicate injections is not more than 2.0 per cent.

Inject the reference solution and the test solution.

Calculate the content of C22H30N6OS, 2½ HBr, xH2O.